M3.5 x 7 10 12 16 20 mm Computer PC Case Aluminum Alloy Knurled Thumb Screws

Most ATX and mATX cases manufactured for the consumer market use M3.5 thumb screws for side panels and expansion slot covers. Check your case manual or measure the thread diameter of an existing screw with a caliper — M3.5 measures approximately 3.5 mm across the thread crests. Some older cases and server chassis use #6-32 UNC (imperial) threads, which are not compatible.

For a single thin panel (typically 0.8–1.0 mm steel), the 7 mm or 10 mm length is usually sufficient. If you are fastening through a thicker bracket, a rubber grommet, or stacking two panels, choose 12 mm or 16 mm. The 20 mm option suits deeper assemblies or applications where extra thread engagement is needed for vibration resistance.

Aluminum alloy thumb screws are designed for panel retention, not structural load-bearing. For PC side panels and expansion slot covers — which experience minimal mechanical stress — they provide adequate clamping force when hand-tightened. Avoid over-tightening with tools, as this can strip the threads or crack the knurl head.

Anodizing is an electrochemical process that converts the surface aluminum into aluminum oxide, integrating the color into the metal rather than coating it. Under normal indoor use — repeated hand-tightening and removal — the finish is durable. Prolonged exposure to harsh chemicals or abrasive surfaces can wear the anodized layer over time.

Yes. Any application with M3.5 threaded inserts or standoffs that requires frequent manual access is a suitable use case. Common examples include 3D printer frame panels, DIY electronics project boxes, and rack-mount equipment with tool-free access panels. Confirm the thread specification of your enclosure before ordering.

For a neutral, understated look that matches most chassis, Silver or Black are the most versatile choices. If you are building a themed system — for example, a red-and-black build — Deep Red or Gold can serve as accent fasteners visible through a tempered glass side panel. The anodized finish ensures the color remains consistent across the pack quantity you order.

M3 screws have a 3.0 mm thread diameter and M3.5 screws have a 3.5 mm thread diameter. They are not interchangeable — forcing an M3 screw into an M3.5 hole will result in a loose, unreliable fit, and attempting to thread an M3.5 screw into an M3 hole will cross-thread and damage both the screw and the standoff. Always verify the thread specification before purchasing.